Walking supporting pier for coal mines

ABSTRACT

A walking supporting pier for coal mines comprising two props mounted on a common lower frame on a wall, the lower frame supports a common upper frame extended by a front shield which is pivotally connected to its and which itself supports a cowl. The upper and lower faces are connected by two sets of rods each consisting of two pivotally interconnected rods, one of which is pivotally connected to the upper frame and the other pivotally connected to the lower frame. The axes of the three pivotal connections of one set are parallel to one another and perpendicular to the longitudinal median plane of the pier. The three axes of the pivotal connections of one of the sets coincide respectively with the three axes of the other set.

llnited States Patent [191 Alacchi Dec. 24, 1974 WALKING SUPPORTING PIER FOR COAL MINES [76] Inventor: Georges Alacchi, 9 ter Cours Fauriel, Saint-Etienne, France [22] Filed: Sept. 12, 1973 [21] Appl. No.: 396,568

[52] U.S. Cl 61/45 D [51] Int. Cl E2ld 15/44 [58] Field of Search 61/45 D, 63; 299/11, 31,

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,040,728 5/1953 France 61/45 D 831,275 3/1960 Great Britain 862,921 3/1961 Great Britain 61/45 D Primary Examiner-Dennis L. Taylor Attorney, Agent, or FirmDennison, Dennison, Townshend & Meserole [57] ABSTRACT A walking supporting pier for coal mines comprising two props mounted on a common lower frame on a wall, the lower frame supports a common upper frame extended by a front shield which is pivotally connected to its and which itself supports a cowl. The

upper and lower faces are connected by two sets of rods each consisting of two pivotally interconnected rods, one of which is pivotally connected to the upper frame and the other pivotally connected to the lower frame. The axes of the three pivotal connections of one set are parallel to one another and perpendicular to the longitudinal median plane of the pier. The three axes of the pivotal connections of one of the sets coincide respectively with the three axes of the other set.

5 Claims, 7 Drawing Figures WALKING SUPPORTING PIER FOR COAL MINES I with greater rigidity and hence with increased stability.

BACKGROUND OF INVENTION Piers of this kind are currently being used in many different forms for mine-working operations, in particular for winning coal.

The various different embodiments which have been proposed hitherto all have serious disadvantages which seriously restrict their use in several cases.

In particular, there is frequently poor contact between the supporting piers and the roof which itself is oftenvery irregular so that the roof is subjected to a pumping effect during displacement of the piers.

In addition, these piers are generally not suited to use in sloping, wide-opening deposits because the props of the piers are connected to the frame of the piers through elastic members which, often subject to deterioration, give rise to' the need for constant maintenance. Finally, protection of the overhang with respect to the zoneof the cutting machine rarely. has all the safety guarantees required.

BRIEFSUMMARY OF INVENTION Accordingly, the .object of the invention is to provide a walking supporting pier which obviates these various disadvantages and which, for this reason, can be used without any particular difficulty even in coal mines where the use of conventional .piers involves certain dangers or gives rise to specific difficult problems.

According to the invention, this object is achieved through a walking supporting pier for coal mines comprising two props mounted on a common lower frame on the wall and supporting a common upper framee'xtended by a front shield which is pivotally connected to it and itself supports a cowl, distinguished by the fact that said upper frameand said lower frame are joined by two sets of rods each consisting of two pivotally interconnected rods, one of which" is pivotally connected to the upper frame'and the other pivotally connected to the lower frame, the axes of the three pivotal connections of one and the same set being parallel to one another and perpendicular to the longitudinal median plane of the pier, whilst the three axes of the pivotal connection of one of the sets merging respectively with the three axes of the other.

This arrangement shows a first advantage of the supporting pier according to the invention which is embodied in the fact that the two sets of rods referred to ensure and maintain strict parallelism between, on the one hand, the common axis of the pivotal connections to the lower frame of the two rodspivotally connected thereto and, on the other hand, the common axis of the pivotal connections to the upper frame of the two rods pivotally connected thereto. Taking into account the position of the pivotal connections of said rods, each of the sets of rods is situated in a plane perpendicular to that of the lower frame of the'pier, and parallel to the longitudinal median plane thereof, whilst the plane of the upper frame of said pier is itself perpendicular to those of said'sets of rods. Accordingly, it can readily be seen that the upper frame is only able to incline relative to the lower frame by pivoting about a geometric axis parallel to the common axes referred to above, and that the perfect geometric definition of the axis about which the upper frame of the supporting pier is'able to pivot relative to the lower frame thereof provides the pier Further features and advantages of the invention will become apparent from the following description, given purely by way of example, of one embodiment of the supporting pier in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagrammatic view, in the form of a longitudinal median section on the line l l of FIG. 2, of a supporting pier according to the invention.

FIG. 2 is a diagrammatic view from the left of the supporting pier shown in FIG. 1.

FIG. 3 is a partial diagrammatic view of the pier shown in FIG. 1 showing one of the sets of rods of said pier as seen from the front, FIG. 3a, and from the left, FIG. 3b.

FIG. 4 is a partial diagrammatic view of the pier according to FIG. 1 showing in detail the pivotal connections of the connecting jack of the pier according to FIG. 1, as seen on the one hand from the front with the two lower and upper frames of the pier, FIG. 4b, and on the other hand from the right with the lower frame,

FIG. 4a, and finally from the left with the upper frame, FIG. 40. l

DESCRIPTION OF PREFERRED EMBODIMENT As can be seen from FIG. 1, the walking supporting pier according to the invention comprises two props 1 and 2 whose vertical axes are situated in the longitudinal median plane of the pier. These props 1 and 2 are each pivotally connected, on the one hand to a lower frame 7 through a ball joint situated at its lower end, the centres of the ball joints being shown at 3 and 5, respectively, in FIG. 1, and on the other hand to an upper frame 8 through a ball joint situated atitsupper end,

. the centres of these ball joints beingshownat 4 and 6,

respectively, in FIG. 1.

In addition, the upper and lower frames 7 and 8 are connected to one another through two sets of two rods 9, l0 and 11, 12, the four rods all being equal inlength and the two sets being situated symmetrically on either side of the median longitudinal plane of thepier. Thus, the lower rods 9 and 1 l of each of the sets are pivotally connected to the lower frame 7 through pivotal connections l6 and 13, respectively, whose axes themselves coincide on a common straight line perpendicular to the longitudinal median plane of the pier. Similarly, the upper rods 10 and 12 of each of the sets are pivotally connected to the upper frame 8 through pivotal connections 18 and 15, respectively, whose axes also coincide on a common straight line perpendicular to the longitudinal median plane of the pier. Accordingly, each of the sets of rods finally consists of a lower rod 9 or 11 and an upper rod 10 or 12 which are pivotally connected to one another through a pivotal connection 17 or 14, the axes of these two pivotal connections 17 and 14 themselves again coinciding on a common straight line perpendicular to the longitudinal median plane of the pier.

By virtue of the arrangement of these two sets of rods 9, l0 and ll, 12, as described in the foregoing, each of them remains in a vertical plane perfectly perpendicular to that of the lower frame 7, in the event of any variation in the length of the props l and 2, the angle formed by the two rods of one set, which is always equal to that formed by the two rods of the other set, being arbitrary a priori, but advantageously between 45 and 135. Finally, the upper frame 8 which, through the disappearance of the coincident axes 18 and 15, is forced to remain perpendicular to the planes of the two sets of rods 9, l and l1, 12, is only able to pivot relative to the lower frame 7 about a geometric axis whose direction is entirely specific, namely perpendicular to the longitudinal median plane of the pier.

In addition, at least one of the blocks integral with the lower frame 7, in each of which the ball joint at the lower end of one of. the props l and 2 is designed to slide, is connected through a connecting jack 19 to the block integral with the frame 8 in which the ball joint at the upper end of the other prop is designed to slide. The lower end of the jack 19 is pivotally connected to the corresponding block through a pivot pin 20 passing through the centre of the ball joint articulated in said block and perpendicular to the median plane of the pier, whilst the upper end of said jack 19 is pivotally connected to the corresponding block through a pivot pin 21 passing through the centre of the ball joint articulated in said block parallel to the pin 20.

Accordingly, it is possible by fixing the lengths of the two props l and 2 and the length of the connecting jack [9 completely to determine the position of the centres 4 and 6 of the corresponding ball joints and, hence, the position of the upper frame 8 relative to that of the lower frame 7. In addition, the upper frame 8 supports a cowl 22 through two pivotal connections 23 and 24 whose axes are situated in their mutual extensions parallel to the frame 8 and in the longitudinal median plane of the pier. This cowl 22 carries a conventional elastic cushion 25 filled with water under pressure. It can readily be seen that, by fixing the lengths of the props l and 2 and of the connecting jack 19, the cowl 22 is able to occupy the exact position required by the respective directions of the roof and of the wall. The upper frame 8 is extended by a front shield 26 pivotally connected to the frame 8 about an axis 26a perpendicular to the longitudinal median plane of the pier. In the same was as the upper frame 8, this front shield 26 supports a cow] 27 which is provided with a cushion 28 of water under pressure and which is pivotally connected through pivotal connections 29 and 30 whose axes are situated in their mutual extension parallel to the plane of the front shield 26 and in the longitudinal median plane of the pier.

This front shield 26 is kept in contact with the roof through a shield jack 31 pivotally connected at its ends to the upper frame 8 and the front shield 26, respectively, about axes 31a and 31b parallel to the axis 26a.

Between workings, the pier shifts, as is well known,

by means of a shift beam 32 to which are coupled three successive piers each identical with the other which are connected to the shift beam 32 through a shift jack 33 pivotally connected to it at one of its ends through a pivot pin 33a and to the lower frame 7 of the pier at its other end through a parallel pin 33b. The shift beam 32 can further comprise a front prop 34 which increases the contact pressure with the roof of the water cushion 20 of the front shield 26.

I claim:

1. A walking supporting pier for coalmines comprising two props mounted on a common lower frame on the wall and supporting a common upper frame extended by a front shield which is pivotally connected to it and which itself supports a cowl, distinguished by the fact that said upper frame and said lower frame are connected by two sets of rods each consisting of two pivotally interconnected rods, one of which is pivotally connected to the upper frame and the other pivotally connected to the lower frame, the axes of the three pivotal connections of one set being parallel to one another and perpendicular to the longitudinal median plane of the pier, whilst the three axes of the pivotal connections of one of the sets coincide respectively with the three axes of the other set.

2. A walking supporting pier as claimed in claim 1, distinguished by the fact that the two props are pivotally connected to the lower frame and to the upper frame through one ball joint at the lower end and another ball joint at the upper end of each prop, and by the fact that the two said props are connected by at least one connecting jack pivotally connected to the block of the ball joint at the lower end of one of the props and to the block of the ball joint at the upper end of the other prop, the pivot axes of said connecting jack each passing through the centre of the corresponding ball joint.,

3. A walking supporting pier as claimed in claim 1, distinguished by the fact that the upper frame supports a cow] pivoted about two coincident axes situated in the longitudinal median plane of the pier and parallel to the upper frame, said cowl being designed to support a cushion of water under pressure.

connected to the upper frame supports a cowl pivotally connected to said shield about an axis perpendicular to the pivot axis between said upper frame and said front shield and parallel to the plane of said front shield.

5. A walking supporting pier as claimed in claim 4,

distinguished by the fact that application of the shield I to the roof is reinforced by a prop mounted on a shift beam to which said supporting pier is coupled. 

1. A walking supporting pier for coalmines comprising two props mounted on a common lower frame on the wall and supporting a common upper frame extended by a front shield which is pivotally connected to it and which itself supports a cowl, distinguished by the fact that said upper frame and said lower frame are connected by two sets of rods each consisting of two pivotally interconnected rods, one of which is pivotally connected to the upper frame and the other pivotally connected to the lower frame, the axes of the three pivotal connections of one set being parallel to one another and perpendicular to the longitudinal median plane of the pier, whilst the three axes of the pivotal connections of one of the sets coincide respectively with the three axes of the other set.
 2. A walking supporting pier as claimed in claim 1, distinguished by the fact that the two props are pivotally connected to the lower frame and to the upper frame through one ball joint at the lower end and another ball joint at the upper end of each prop, and by the fact that the two said props are connected by at least one connecting jack pivotally connected to the block of the ball joint at the lower end of one of the props and to the block of the ball joint at the upper end of the other prop, the pivot axes of said connecting jack each passing through the centre of the corresponding ball joint.
 3. A walking supporting pier as claimed in claim 1, distinguished by the fact that the upper frame supports a cowl pivoted about two coincident axes situated in the longitudinal median plane of the pier and parallel to the upper frame, said cowl being designed to support a cushion of water under pressure.
 4. A walking supporting pier as claimed in claim 3, distinguished by the fact that the front shield pivotally connected to the upper frame supports a cowl pivotally connected to said shield about an axis perpendicular to the pivot axis between said upper frame and said front shield and parallel to the plane of said front shield.
 5. A walking supporting pier as claimed in claim 4, distinguished by the fact that application of the shield to the roof is reinforced by a prop mounted on a shift beam to which said supporting pier is coupled. 